xref: /petsc/src/benchmarks/PetscMemcpy.c (revision abdd934af67c1cc360c4d0cfcf2de16e188d627e)

#include <petscsys.h>
#include <petsctime.h>

int main(int argc, char **argv)
{
  PetscLogDouble x, y;
  PetscScalar   *A, *B;

  PetscCall(PetscInitialize(&argc, &argv, 0, 0));
  PetscCall(PetscCalloc1(8000000, &A));
  PetscCall(PetscMalloc1(8000000, &B));

  for (i = 0; i < 8000000; i++) {
    A[i] = i % 61897;
    B[i] = i % 61897;
  }
  /* To take care of paging effects */
  PetscCall(PetscArraycpy(A, B, 8000000));
  PetscCall(PetscTime(&x));
  PetscCall(PetscArraycpy(A, B, 8000000));
  PetscCall(PetscTime(&x));

  fprintf(stdout, "%s : \n", "PetscMemcpy");
  fprintf(stdout, "    %-15s : %e MB/s\n", "Bandwidth", 10.0 * 8 * 8 / (y - x));

  PetscCall(PetscFree(A));
  PetscCall(PetscFree(B));
  PetscCall(PetscFinalize());
  return 0;
}